Fan



Jan. 20, 1942. G. F. BAHR 2,270,574.

FAN

Filed Aug. 25, 1937 2 Sheets-Sheet l -INVENTOR ATTOR G- F. BAHR FAN Filed Aug. 25, 1937 2 Sheets-Sheet 2 INVENTQR @MQW A qhr Patented Jan. 20, 1942 NETE FAN

Gustave F. Bahr, Fairfield, Conn., assignor to Casco Products Corporation, Bridgeport, Conn., a corporation of Connecticut ApplicationAugust 25, 1937, Serial No. 160,806

13 Claims.

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ment.v rl'he sections of the hub need not be slotted after the casting operation, as in prior constructions, but each section can be formed with its final shape ready to receive the blades upon assembly. These features of the invention reduce the cost of production of the fan by saving several operations in the forming of the hub and doing away with the usual manipulation of the blade necessary to insert it and hold it in slots of a hub. Means are provided whereby after the sections have been assembled and the blades locked therein, the hub and blades can be secured to a drive shaft.

Accordingly, the blades of the present invention when clamped between the hub sections are se,- curely held against outward movement due to centrifugal forceby the slots into which they are positioned. v

In one form of the invention, a two part hub is provided having the line of jointure of the two parts formed so as to provide a plurality of bladereceiving slots extending helically along the surface of the hub. Located axially of the hub so as not to destroy the dynamic balance of the fan is a draft means whereby the two sections of the hub are drawn into clamping relation with the blades. With this construction the hub sections are separated and the blades are positioned along the edge thereof so as to lie within the slots formed by the two sections when the hub sections are associated. The two sections are then associated and drawn into place by the draft means. This eifectively clamps the blades and holds them in fixed position without the necessity of the use of additional elements to act as securing means for the blades to hold them to the hub. The draft means in this form of the invention also serves a second function since it has associated therewith a clamping element adapted to slide in a bore in one section of the hub` and be moved into gripping relation with the end of the drive shaft by operation of the draft means. In this form of the invention there is provided, therefore, a common means for both securing the blades to the hub and the hub to the motor shaft. Initial operation of the draft means will cause the sections to move into gripping relation with theblades. The hub is then placed on the end of' a motor shaft and continued movement of the draft means causes the clamping means to grip the end lof the drive shaftl so that the blades are securely gripped to the hub and the hub and blade securely mounted on the drive shaft in one operation.

In another form ofthe invention a pair of members are provided, one of which has a smooth rounded nose-portion adapted to project for-..

wardly of theblades. The two sections of the hub are formed so that the blades can be gripped by them and held in place. In this form of the invention, the means for securing the sections together is mounted axially of the hub and is operable from the back of the hub so that the outside surface of the hub is smooth and free from any depression. A separate means is carried by a sleeve on one section of the hub whereby, after the two sections have been securely clamped together, the hub and the blades can then be secured to the motor shaft.

The fan blades used according to the present invention may be provided with an enlargement extending along the edge of the blade adapted to engage the hub in view of the fact that the blades do not have to be manipulated to be passed through the slot but can be merely laid in the slots when the sections of the hub are separated with the enlargement engaging the inner wallfof the hub. Because this form of blade can be used,it eiectively aids the'y clamp in holding the blade from outward movement due-to centrifugalk force.

Another form of blade disclosed is one wherein the blade is provided with a metal reinforcing memberor insert which is positioned in the hub and adapted to be gripped thereby to hold the blade on the hub. While not absolutely necessary it is desirable to form a flange on the metal member which will engage the hub to assist in resisting outward movement of the blades. With this construction the insert which is adapted to be gripped by the hub can be of less width than the blade. The blades can be positioned to overlap one another and still be effectively held in position by the clamping action of the two hub members.

Other features and advantages of the invention will be apparent from the specification taken in connection with the drawings, of which:

Figure l is a front view of the hub and blades in assembled relation.

Fig. 2 is a side view of Fig. 1. Fig. 3 is a side view of the hub alone. Fig. 4 is an exploded view of the hub. (Fig. 5 is a section ,of the blades and hub taken along lines 5--5 of Fig. 1.

Fig. 6 is a plan view of the blade.

Fig. 7 is an end view of Fig. 6`

Fig. 14 is a side view of theback hub section.

Fig. 15 is an end view of Fig. 14 looking from the left.

Fig. 16 is a sectional view taken along lines lli-I6 of Figs. 13 and 15 with the sections in assembled relation.

Fig. 17 shows a portion of the blade with the metal insert attached thereto.

Fig. 18 is a plan view showing a portion of the blade with its metal insert.

Fig. 19 shows a portion of the blade with the metal insert molded therein.

As shown in Fig. l, the fan comprises a hub having three blades mounted thereon. While three blades are shown in the drawings it is obvious that any desired number of blades may be used.

According to prior practice the hub was molded in one piece and the slots for receiving the blades were then formed by a separate piercing operation. This required much time and handling of the work. Accordingly, the hubs of the present invention are formed of a plurality of sections and assembled so that they automatically form the slots. 'Ihe preferred form of hub is shown as comprising only two sections, a front section 20 and a rear section 2l. It is obvious, however, that any number of parts or sections may be used and assembled.

'I'he sections, according to the present invention, are molded or diecast into their nal shapes so that when they are assembled the two sections will form along their line of jointure a plurality of helically disposed slots 22 extending along the hub toward the front thereof and this eliminates the forming of the slots by a separate operation. The front of the hub 20 is provided with a sleeve 23 adapted to receive a sleeve 24 on the back section of the hub. These sleeves are preferably formed integrally with the hub section, but it is obvious that they may be made separately and secured thereto if desired. The front section of the hub is formed with an axially-extending hole 25 having the outer end recessed to receive the head of a bolt 26 extending through the hole so that the same lies within the surface of the hub. The sleeve 24 has an end wall 24a provided with an axial hole through which the screw 26 passes for locking the two elements in assembled relation.

It is essential that there should be no relative rotation between the two sections of the hub and accordingly one section is provided with a key 32 adapted to slide in a keyway 33 formed in the other sleeve when assembled.

A plurality of blades 35 are adapted to be mounted in and securely held in the slots in the hub. Heretofore it was necessary to manipulate the blades in order to position them in the slots. Because of the limited space, this was a tedious operation which consumed time. According to the present invention, however, when it is desired to assemble the blades and hub it is merely necessary to separate the hub sections and position the blades in the slots. And, although the blades are provided with an enlargement 36 on the hub-engaging edge which is adapted to engage the inner surface of the hub and aid the clamping action of the slots in holding the blade in position against the action of centrifugal force, they may be quickly and easily placed in slots formed by the separated hub sections. The two 4hub sections are then moved together in gripping relation with the blades and the draft means turned to lock them in this position.

In order to mount the hub and blades on the drive shaft, a clamping sleeve 2l is slidably mounted in the bore of the sleeve 24 and is slotted at one end to form gripping elements 28. The other end of the clamping sleeve is threaded to engage the screw 26 and be moved thereby. The outer ends of the clamping elements are provided with cam surfaces 29 adapted to coact with cam surfaces l30 formed in the bore of the sleeve 24 so that upon turning of the screw 26 the clamping sleeve is moved into sleeve 24 causing the cam surfaces 29 and 30 to move the gripping elements into gripping relation with a driving shaft 3| which is adapted to bepositioned within the clamping sleeve as clearly shown in Fig. 5.

According to the present invention, it will be noted that, a common means is provided for both locking the blades to the hub and also locking the hub and blades to the drive shaft. Initial rotation of the screw 26 will cause the gripping sleeve and section 2| to move into locking engagement with the hub section 20 to hold the blades. As soon as these are moved into assembled relation the hub and blades are positioned on the drive shaft so that the same extends within the clamping sleeve 21. Continued rotation of the screw 26 will draw the clamping sleeve into the bore and will cause the gripping elements to securely hold the hub and blades upon the shaft. It will be seen that the assembling operation is simple and avoids unnecessary manipulation of the parts usually required in assembling the blades on the hub.

As shown in Fig. 8, the blades have a generally tapered form being thickest at the point at which they are clamped by the hub. It will also be noted in Fig. 1 that in this form of the invention the blades have been positioned so that they do not overlap one another. g

In another form of the invention, however, as shown in Fig. 9, the blades are formed so as to overlap one another. In this form of the invention the hub is made with a front portion 40 having a smooth, rounded nose-surface and a rear section 4I having a reduced neck 4Ia extending rearwardly therefrom as shown in Figs.

11 and 16. These two sections are molded directly into their final form. The line of jointure of these sections is so formed that when the sections are secured together helical slots 42 will be formed in the hub extending forwardly therealong.

The front section 40 is provided with an inward projection 43 extending axially of the hub and having a recess 44 adapted to receive a sleeve 45 formed integrally with the hub section 4I. The recess 44 is provided with a threaded section extending beyond the sleeve-receiving section and positioned axially of the hub section 40 for receiving the securing means to be later described. Sleeve 45 is provided with an end wall 46 having an aperture axially thereof through which a screw 41 passes into threaded engage'- ment with the threaded section in hub 40, the

head of the screw bearing against the wall 45. This effectively locks the two sections together.

A plurality of blades 55 are adapted to be secured to the hub. The blades in this form of the invention are provided with a metal insert or anchoring means 56 secured to the edge of the blade adjacent the hub by rivets or other suitable means. The insert is adapted to be positioned in the slot and clamped therein. The metal insert has a iiange 5l which is adapted to engage the inner wall of the hub to assist the clamping action of the two section of the hub on the blade in preventing the blade from ying out due to centrifugal force.

Another form of blade is shown in Fig. 19 wherein the blade 55' is provided with an insert 56 molded therein. The metal insert has the flange 5l for engaging the back of the hub as previously described.

In assembling the blades and hub in this form of the invention, the two hub sections are separated and the anchoring means for the blades are positioned in the slots with the flange 5'! or 5l engaging the inner wall of one of the hub sections. The sections are joined and the screw tightened and the blades locked in position.

With blades of the type shown in this form of the invention, it is obvious that they can be made to overlap, if desired, since they can extend beyond the edges of the anchoring means as shown in Fig. 18.

The hub of this form of the invention is provided with means, operable independently of the means for securing the blades to the hub, for

locking it to the drive shaft so that the hub sections which may be assembled and locked can be mounted on the shaft without disturbing their assembled relation. Accordingly, a second sleeve 48 is formed to project from the hub section 4I within the rearward extension A la and is adapted to receive the drive shaft 3|. This sleeve is provided with a set screw 49 positioned in alignment with an aperture 50 in the rearward extension 41a through which a tool can be inserted to adjust the set screw to lock the hub to the drive shaft.

It is to be distinctly understood that any of the blades herein disclosed maybe used with either form of hub construction. Also the two sections of the hub can be permanently secured together, if desired, by extending a tube or rivet through the sections and spinning over the ends thereof or by any equivalent means.

In the event that the fan and blades, when assembled on the drive shaft, are out of balance, a

small amount of weighting material, preferably wax, can be supplied on the inside of the hub in order to balance the fan.

Variations and modifications may be made withinthe scope of this invention and portions of the improvements may be used without others.

I claim:

l. In a fan, a plurality of blades; a hub comprising two sections formed with slots on their peripheral line of jointure, and inclined to the axis of the hub in order to determine the pitch of said blades, said sections adapted to engage said blades having mutually interfitting male and female sleeves respectively, positioned adjacent the axis of said sections and co-axial with the hub; and means for locking the sections in clamping relation with the blades; mutual intertting engagement of the sleeves reenforcing the hub against relative lateral displacement of said sections, and the interior of one of the sleeves forming a socket for receiving the end of a shaft.

2.' In a fan, a drive shaft; a plurality of flexible blades; a two-part hub member, the two parts of said hub member having annular anges provided with a plurality of pairs of comparatively narrow companion meeting edges inclined relative to the axis of rotation of the shaft and forming, when assembled together, an ellipsoidal shaped hub member; and clamp means operative by a single actuation for clamping the two parts of the hub member togetherwith the blades nterposed between said meeting -edges and for securing the assembled hub member parts and blades to an end of the drive shaft.

3. In a fan, a drive shaft; a plurality of fiexible blades; a two-part hub member, the two parts of said hub member having annular flanges provided with a plurality of pairs of comparatively narrow companion meeting edges inclined relative to the axis of rotation of the shaft and forming, when assembled together, an ellipsoidal shaped hub member; andv means for retaining the said two parts assembled relative to each other with said blades interposed between said meeting edges, said means including clamp means made operative by the actuation of said hub-retaining means for securing the assembled hub member to an end of said shaft.

4. In a fan, a drive shaft; a plurality ofv exible blades; a two-part hub member, the two parts of said hub member having annular anges provided with a plurality of pairs of comparatively narrow companion meeting edges inclined relative to the axis of rotation of the shaft and forming, when assembled together, an ellipsoidal l shaped hub member; and means for retaining the said two parts assembled relative to each other with said blades interposed between said meeting edges, said means including means for gripparts of said hub member having annular flanges provided with a plurality of pairs of comparatively narrow companion meeting edges inclined relative to the axis of rotation of the shaft at the desired pitch angle for the blades and forming,

when assembled together, an ellipsoidal shaped hub member; an internal sleeve axially carried by each part, said sleeves intertting when the parts are assembled and reinforcing said hub; means within the sleeves and coaxial with the shaft for gripping the sides of the shaft with a 'radial' pressure; and means for operating said last-named means'to secure the assembled hub to said shaft, said means including means for retaining the two parts of the hub member and ,n blades assembled.

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vided with a plurality of pairs of comparatively` narrow companion meeting edges inclined relative to the axis of rotation of the shaft at the means carried by one sleeve and cooperating withv means formed on the other sleeve for preventing relative rotation between the said parts; and common means for clamping the two parts of the hub member together with the blades interposed between said meeting edges and for securing the assembled hub member parts and blades to the end of the drive shaft.

7. A fan comprising a hollow base member having a circumferential flange formed with a plurality of inclined edges; a hollow cap member having a plurality of similarly inclined complemental edges; a exible blade of rubber or the like between each coacting pair of inclined edges of the cap and base member; a drive shaft; and a unitary means within said base member for clamping the cap member to said base member with the flexible blades between each coacting pair of inclined edges of the cap and base member and for simultaneously securing the clamped together cap and base member to the end of the drive shaft.

8. A fan comprising a motor having a drive shaft; a hollow base member having a circumferential flange formed with a plurality of inclined edges and having a sleeve positioned axially thereof; a hollow cap member having a plurality of similarly inclined complementary edges and a sleeve of a diameter larger than said first-named sleeve positioned axially of the same, said sleeves interftting when the two members are assembled with the edges in juxtaposed position; a flexible blade of rubber or the like between each coacting pair of inclined edges of the cap and base member; means carried within the sleeve of said base member for firmly clamping the cap and base member together; and means made operative upon operation of said last-named means for securing the assembled members and blades to the end of the drive shaft.

9. A fan comprising a motor having a shaft; a base member; a cap member, said members being formed with complemental inclined gripping portions and flexible fan blades of rubber or the like gripped and held between said gripping portions, the inclination of said gripping portions being such as to force said flexible blades to and hold them in proper angular relation to each other for propelling air when the fan is rotated, said base member and cap member being hollow and each formed with intertting sleeves positioned axially within said member; means within the smaller sleeve for clamping the assembled cap and base member to the drive shaft comprising camming surfaces and cooperating clamping elements extending axially of the cap and base member and positioned to engage the sides of the drive shaft for a substantial area thereof; and means extending axially of the shaft for moving the clamping elements relative to the camming surfaces and laterally with respect to the shaft into clamping relation therewith to lock the cap and base member thereto, said means simultaneously clamping the cap and base member together.

10. A fan comprising a motor having a shaft; a hub member comprising a hollow base member provided with a circumferential flange formed with a plurality of inclined edges and a hollow cap member having a plurality of similarly inclined complementary edges; an internal sleeve axially carried by each member, said sleeves intertting when the members are assembled with the edges in juxtaposed position and reinforcing said hub; a iiexible blade of rubber or the like between each coacting pair of inclined edges of the cap and base member; a camming surface disposed within the bore of the smaller sleeve; clamping elements mounted to slide in the bore of said sleeve and having parts adapted to engage the camming surface; and means for sliding the clamping elements to move them relative to said camming surface to cause them to move laterally to clamp the drive shaft and hold the hub thereon against relative movement, said last-named means being operative simultaneously to clamp the cap and base member together with the ilexible blades between the inclined edges thereof at the proper angle for propelling air when the shaft is rotated.

11. A fan comprising a hollow base member having a circumferential flange formed with a plurality of inclined edges, a hollow cap member having a plurality of similarly inclined complemental edges, a flexible blade of rubber or the like between each coacting pair of inclined edges of the cap and base member; a motor having a drive shaft; and means for clamping the cap and base member together and for securing the clamped together cap and base member to the drive shaft comprising a sleeve internally carried by the base member mounted to extend axially thereof and provided with a camming surface in its' bore and a clamping sleeve slidable in the bore and having one end slit so as to form clamping elements adapted to cooperate with the clamping surface in the bore, the other end threaded to engage a bolt mounted in the cap to extend axially of the same whereby when the bolt is turned the clamping sleeve will slide and move the clamping elements laterally into gripping relation with the shaft and move the base axially of the shaft into clamping relation with the cap.

12. In a fan, a plurality of blades; a hub comprising a pair of hollow sections having portions of their peripheral lines of jointure adapted to engage said blades and inclined to the axis of the hub in order to determine the pitch of the blades, each section having an internally disposed sleeve coaxial with the hub, said sleeves interfitting with each other in male and female relation when the hub is assembled, whereby the hub is reenforced against relative lateral displacement of the two sections, and one of said sleeves forming a socket for receiving the end of a shaft; mutually interlocking means carried by said sleeves for preventing relative rotation between said sections; and means for locking said sections together against separation at the line of jointure.

13. A fan comprising a hollow base member having a circumferential flange formed with a plurality of inclined edges; a hollow cap member having a plurality of similarly inclined complemental edges; a flexible blade of rubber or the like between each coacting pair of inclined edges of the cap and base member; a drive shaft; clamp means within said base member; and means engageable exteriorly of said cap member for actuating said clamp means, said clamp means adapted when made operative by operation of said actuating means to clamp the cap member to said base member with the flexible blades between each coacting pair of inclined edges of the cap and base member and simultaneously secure by the same operation the clamped together cap and base member to the end of the drive shaft.

GUSTAVE F. BAHR. 

